Remove hacks for displaying lists in tables

get_display_data_single() should not do any transformation of
a supplied data in order to let Cliff's serializers to do that
in a way a user choses.

Change-Id: Ifb98fce21b6363296c87f67d05ee301943fa72b4
Closes-bug: #1548764

fuelclient/common/data_utils.py

@@ -12,6 +12,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from fuelclient.cli import error
+
 
 def get_display_data_single(fields, data):
     """Performs slicing of data by set of given fields
@@ -25,24 +27,11 @@ def get_display_data_single(fields, data):
                    supplied attributes.
 
     """
-    result = []
-
-    for field in fields:
-        if field not in data:
-            raise KeyError('{f} is not found in the supplied '
-                           'data.'.format(f=field))
-
-        val = data.get(field)
-
-        if not val and val not in (0, None, False, ''):
-            val = '-'
-
-        if isinstance(val, list):
-            val = ', '.join(str(item) for item in val)
-
-        result.append(val)
-
-    return result
+    try:
+        return [data[field] for field in fields]
+    except KeyError as e:
+        raise error.BadDataException('{} is not found in the supplied '
+                                     'data.'.format(e.args[0]))
 
 
 def get_display_data_multi(fields, data):

fuelclient/tests/unit/common/test_utils.py

@@ -193,31 +193,17 @@ class TestUtils(base.UnitTestCase):
                          error_body.decode('utf-8'))
 
     def test_get_display_data_single(self):
-        test_data = {'a': 1, 'b': 2, 'c': 3}
-        fields = ('b', 'c')
-
-        result = data_utils.get_display_data_single(fields, test_data)
-        self.assertEqual([2, 3], result)
-
-    def test_get_display_data_single_empty_val(self):
-        test_data = {'a': 1, 'b': {}, 'c': []}
+        test_data = {'a': 1, 'b': [], 'c': [1, 2, 3], 'd': 4}
         fields = ('a', 'b', 'c')
 
         result = data_utils.get_display_data_single(fields, test_data)
-        self.assertEqual([1, '-', '-'], result)
-
-    def test_get_display_data_single_list_val(self):
-        test_data = {'a': 1, 'b': ['2'], 'c': ['3', '4']}
-        fields = ('a', 'b', 'c')
-
-        result = data_utils.get_display_data_single(fields, test_data)
-        self.assertEqual([1, '2', '3, 4'], result)
+        self.assertEqual([1, [], [1, 2, 3]], result)
 
     def test_get_display_data_bad_key(self):
         test_data = {'a': 1, 'b': 2, 'c': 3}
         fields = ('b', 'bad_key')
 
-        self.assertRaises(KeyError,
+        self.assertRaises(error.BadDataException,
                           data_utils.get_display_data_single,
                           fields, test_data)